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Staphylococcus 7

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8 Staphylococcus

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Staphylococcus 9 Staphylococcal protein A (SpA) Type I membrane protein It is a surface protein covalently bound to the peptidoglycan layer Inhibits antibody mediated clearance by binding with IgG1, IgG2 and IgG4 Fc receptors Z domain contains three alpha helices which are arranged in an antiparallel three-helix bundle Hypothetical mechanisms for binding to human IgG antibodies by an IgG-binding domain of SpA. (a) A rearrangement mechanism , in which there are minor structural changes in the relative orientation of helix 1 in going from the free to the IgG-bound state. (b) Direct binding mechanism in which the orientations of the three α-helices are identical in the free and IgG-bound states. Montelione etal; Journal of Molecular Biology Volume 272, Issue 4, 3 October 1997, Pages 573–590

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Staphylococcus 10 Staphylococcus aureus protein A bound to Fab (1DEE) and bound to an immunoglobulin Fc in its minimized form (1L6X) Source: Wikipedia

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Staphylococcus 17

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Staphylococcus 18

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Staphylococcus 19 Regulation of ß-lactam resistance. BlaR1, 2 and MecR1, 2 represent proteins that detect ß-lactam antibiotics in the environment. Once the antibiotics are detected, the BlaR2 or MecR2 proteins become activated, and degrade the BlaI or MecI proteins. As a result resistance proteins (ß-lactamase or PBP2a) are produced and render the cell resistant to these antibiotics.

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Staphylococcus 31 Spectra MRSA medium plated with methicillin-resistant Staphylococcus aureus . The ability of Spectra MRSA to identify methicillin-resistant S. aureus based on the color of the colony, in which colonies of methicillin-resistant S. aureus appear denim blue, is shown.

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Staphylococcus 33 Methicillin resistance gene SCCmec elements commonly share the following characteristics. (1) They carry a mec gene complex (mec). (2) They carry a ccr gene complex (ccr). (3) They have characteristic directly-repeated nucleotide sequences and inverted complementary sequences at both ends. (4) They integrate into ISS (integration site sequence for SCC), which is located at 3’ end of orfX.

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Staphylococcus 34 SCC mec type: defined by the combination of mec and ccr Subtypes: Defined by the structural differences in J1, -2 and -3 regions

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Staphylococcus 35 http://web.mit.edu/angles/Oran_Payne.htm

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Staphylococcus 36 Staphylococcus Bacteriophage typing Phage groups Group I Group II Group III Group IV Others